GC-MS profiling and efficacy of Crotalaria ramosissima Roxb. leaf extracts in controlling termite, Odontotermes obesusH. A. LANCHANA1, S. BASAVARAJAPPA2 and RAJKUMAR H. GARAMPALLI1*1Department of Studies in Botany, University of Mysore, Manasagangotr

Crotalaria ramosissima Roxb. is a Fabaceae family genus that prolifically grows as a weed in southern regions of India and is known for insect-repellent activity. The purpose of the current study is to assess the efficacy of anti-termite activity of the different solvents extracts and formulations of C. ramosissima against Odontotermes obesus which is prevalent in the south dry zone that destroys 10% of crops and wood on an average by feeding. The extracts showed anti-termite efficacy by No-choice bioassay method where the ethyl acetate extract showed highest termite mortality rates of 24.23±1.51%, 43.93±1.51%, 74.23±1.51% at 12, 24, 36h time intervals and methanol extract showed 16.66±1.51%, 30.29±4.00%, 54.54±2.62% at 12, 24, 36 h time intervals. The TLC analysis of ethyl acetate extract resulted in three bands which were separated through column chromatography and named Fraction-1, Fraction-2, and Fraction-3 and upon further investigation Fraction-3 showed maximum mortality rate of 81.81±2.62% at 36 hrs of time interval with a lethal concentration (LC-50) 248.44mg/ml. The GC-MS profiling of fraction-3 led to the identification of compounds viz. 1,2-benzenedicarboxylic acid, 1,2,4-oxadiazole, 3-(1,3-benzodioxol-5-yl)-5-[2-(4-methoxyphenyl)ethyl, phenmethylamine-2-acetoxy-n,n-bis[2-(benzoimid-2-yl)ethyl], and 9-octadecenoic acid (z)-2-hydroxyethyl ester and phenol, p-(1-ethyl-1-methylbutyl.These results may aid in the synthesis of novel effective bioactive compounds that needs to be explored for their toxicity against insects, as was enlightened in the current study